US forces were planning to carry out naval drills with their South Korean and Japanese counterparts next week, dpa cited officials as saying Thursday. The drills would be held on June 21 and 22 in international waters south of the Korean Peninsula, involving destroyers and logistical support vessels, the Defence Ministry in Seoul said. The simulation would practise disaster relief manoeuvres and future maritime security exercises, it said. The United States has held regular joint naval exercises with both allies since 2008. Following the trilateral manoeuvres, the US forces were to conduct further drills with the South Korean navy in the Yellow Sea, the Defence Ministry said. The annual exercises would practise defence against North Korean submarines, a source told dpa. The nuclear-powered aircraft carrier USS George Washington would also take part in the drill, which the US Department of Defence described as "routine."